None listed
Conditions
Brief summary
The ATAC trial is testing an alternative, new agent, to tamoxifen for women with early breast cancer. The new agent, Arimidex, is an aromatase inhibitor which acts to reduce the level of circulating oestrogen in post menopausal women. This drug seems to be well tolerated and also effective against breast cancer. The ATAC trial is a double blind study comparing 5 years of tamoxifen, with 5 years of Arimidex, and with 5 years of tamoxifen plus Arimidex. In addition, there are three very important sub studies which investigate the effects of the treatments on bone, the endometrium and quality of life (QOL). Australia had a high rate of recruitment to the QOL sub study and is also one of the few countries contributing to the endometrial sub study. The ATAC trial is one of the largest (over 9000 women internationally) and most rapidly completed breast cancer studies in the world. Active accrual to the main study and sub-studies was completed internationally in May 2000, and patient follow-up continues.
Interventions
Patients are randomised to receive one of three treatment regimens:
* Arimidex 1mg orally daily for 5 years + Nolvadex placebo orally daily for 5 years
* Arimidex placebo orally daily for 5 years + Nolvadex 20 mg orally daily for 5 years
* Arimidex 1mg orally daily for 5 years + Nolvadex 20mg orally daily for 5 years
Sponsors
AstraZeneca (formerly known as Zeneca, formerly known as ICI)
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Histologically proven operable invasive breast cancer. Patients who completed all primary surgery and chemotherapy and are candidates to receive hormonal adjuvant therapy. Post-menopausal women according to one or more of the following: a) aged 60 or > b) aged 45-59 and satisfying one or more of the following: i) amenorrhea for at least 12 months and intact uterus ii) amenorrhea < 12 months and FSH within post-menopausal range; including: Patients who have had hysterectomy. Patients who received HRT. Patients rendered amenorrhoeic by adjuvant chemotherapy iii) bilateral oophorectomy.
Exclusion criteria
Clinical evidence of metastatic disease. Patients unlikey to comply with trial requirements. Patients whose chemotherapy started > 8 weeks after completion of primary surgery or whose chemotherapy completed > 8 weeks before starting randomised treatment. Patients who have not received chemotherapy and whose primary surgery completed > 8 weeks before starting randomised treatment. Patients who received previous hormonal therapy as adjuvant treatment for breast cancer, unless: a) this was tamoxifen started prior to first surgical procedure and received < 29 days orb) this was hormonal therapy received pre-surgery in context of a formal trial, approved by Steering Committee. Patients who received tamoxifen as part of any breast cancer prevention trials, e.g. IBIS. Patients unwilling to stop taking any drug known to affect sex hormonal status, or in whom it would be inappropriate to stop. Previous history of invasive breast cancer or other invasive malignancy within last 10 years, other than squamous or basal cell carcinoma of skin or carcinoma in situ of cervix, adequately cone biopsied. Any severe concomitant disease placing patient at unusual risk or confound results of trial. Treatment with nonapproved or experimental drug 3 mths prior to randomisation. Patients at risk of transmitting any infection through blood or body fluids.
Outcome results
None listed